Ivica Dacic said in a strongly-worded statement that Serbia has been under pressure to "diplomatically speaking, balance its foreign policy" with that of the European Union and impose sanctions on Russia.

"Serbia wants to enter the EU but will not do anything that is against its own national interests," Dacic said. "We want good relations with everyone, but we will not work against ourselves."

Officials also said Serbia will send humanitarian aid to Syria and Serbian media have reported the aid will be sent by Russian planes from a Russian-Serbian humanitarian centre in the southern Serbian city of Nis.

"We are not sending weapons, but blankets and medicine, and we will always send it, whoever asks," Prime Minister Aleksandar Vucic said Wednesday.

Dacic insisted in his statement that "we are helping the people of Syria, as we did others, and as we will send help to Syria also if someone else suggests it."

Serbia formally wants to join the 28-nation European Union, but Russia's influence remains strong and Belgrade has refused to impose sanctions against the Kremlin for its role in the Ukrainian crisis.

Moscow has backed Serbia in its dispute with the West over the former province of Kosovo whose 2008 Western-backed declaration of independence Serbia has refused to recognize.